About foreign keys - http://guides.rubyonrails.org/migrations.html#active-record-and-referential-integrity http://guides.rubyonrails.org/migrations.html#active-

About foreign keys - http://guides.rubyonrails.org/migrations.html#active-record-and-referential-integrity http://guides.rubyonrails.org/migrations.html#active-record-... About Lazy Loading at field level it is not really needed in most scenarios. You can do it with your own code if you wanted it that way. Edge case scenarios may be handled differently in most ORMs however with Active Record I never felt the need to write SQL ever. Also for simple checks I use the Rails console to see data whereas with other ORMs I had to open a SQL console.